In recent years, communication through the use of ad hoc networks has become more prevalent. Ad hoc networks are self-forming networks which can operate in the absence of any fixed infrastructure, and in some cases the ad hoc network is formed entirely of mobile nodes. An ad hoc network typically includes a number of geographically-distributed, potentially mobile units, sometimes referred to as “nodes,” which are wirelessly connected to each other by one or more links (e.g., radio frequency communication channels). The nodes can communicate with each other over a wireless media without the support of an infrastructure-based or wired network.
A mesh network is a form of an ad hoc network based on autonomous collections of mobile nodes that communicate with each other over wireless links having limited bandwidths. Individual nodes in a mesh network can perform routing functions, which enable a mesh network to be reconfigured around blocked paths or poor connections by “hopping” from one node to another until a destination is reached. A mesh network is thus described as self-healing, as it can still operate effectively even when particular nodes break down or leave the network.
The lack of a central controller in a mesh network creates a need for new methods to provide efficient end-to-end traffic control such as call admission control (CAC). Call admission control regulates communication quality by limiting the number of calls that can be active on a particular link at the same time. Call admission control does not guarantee a particular level of quality on the link in a mesh network, but it does allow for the regulation of the amount of bandwidth or time consumed by active calls on the link.
As wireless communications networks such as mesh networks become more prevalent, security continues to be a major concern to both communications network providers and end users. In a wireless communications mesh network the security environment can offer the greatest challenges since data may be readily received and manipulated by many nodes. The radio links used in a wireless communications mesh network expose signaling and other data traversing the network to eavesdroppers and/or would-be hackers.
Network Admission Control (NAC) is a set of technologies and solutions which enforce security policy compliance on all devices (i.e. nodes, access points, and the like) seeking to access network resources, thereby limiting damage from emerging security threats. NAC can allow network access only to compliant and trusted devices and can restrict the access of noncompliant devices.
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